434. Any certificate which has been granted by the Government under this Ordinance to any master, mate or engineer may be cancelled, or for a specified period suspended, by the Government in the following cases, that is to say,- (a) if, on receipt of a report under sub section (4) of section 419, or under section 425, or under sub section (4) of section 431, the Government considers cancellation or suspension necessary; (b) if the master, mate or engineer is proved to have been convicted- (i) of any offence under this Ordinance or of any non bailable offence committed under any other law for the time being in force in Bangladesh or an offence involving moral turpitude and so committed; or (ii) of an offence committed outside Bangladesh which, if committed in Bangladesh, would be a non bailable offence or an offence involving moral turpitude; (c) if it has reason to believe that any master, mate or engineer is, or has become, unfit to discharge his duties.